Mill



March 5, 41946.

' L. S. PETERSEN MILLS '2 Sheets-Sheet 1 Filed Oct. 11, 1945 ,....w m. Nw

Y SQA uvm ATTORNEYS March 5, 1946. I l.. s. PETERSEN MILLS Filed OG t. 1.1, 1945 2 Sheets-Sheet 2 ATTORNEYS- Patented Mar. 5, 1946 MILL- Louis S. Petersen, Forest Hills, N. Y., assignorto A Y F. L. Smdth& Co., New York, N. Y., a corpo#r Y ,l y ration of New Jersey 1 i o Applioation ootobor 11, 194s, sonoiNo. 565,725 12 claims'. icl". 14g-.421) y q s' This invention relates to apparatus of the type that includes a generally cylindrical shell mounted for rotation on its longitudinal axis, examples of such apparatus being ball mills, rotary kilns, certain forms ,of dryer, etc. More particularly,

`the invention is concerned witha novel apparatusof the kind mentioned whichvis superior yto prior equipment with` respect to the means by which the shell-is supported and rotated. While' the new apparatus may take various forms, as indicated above, the invention maybe embodied to especial advantage in ball mills and its application to that eld will, accordingly, be illustrated and described in detalfor purposes 'of explanation. -Y u Ball mills consist essentially of agenerally cylindrical shell or drum mounted with its longitudinal axishorizontal and supported for rotation on that axis. The shell is closed at its ends and is provided with an inlet at one end through which material to be ground may be introduced by appropriate means, such as a rotary scoop within a casing, and with an outlet at the other end through which the ground material is discharged. f f

In one prior construction, the shell is formed with hollow trunnions at its ends serving, respectively, as the inlet and the outlet, and the shell is supported by bearings in which the trunnions run. The shell is then rotated rby a master gear which encircles and is secured to the drum and is enclosed within' a casing. 'I'his construction, in'which the entire weight of the drum and its contents is carried bythe trunnions and their bearings, is relatively expensive because of ther large trunnion bearings required.v Also, since the shellv is supported beyond its ends, difficulties may f by a'r'smallguide.bearingpso that the costl of arise because of misalignment caused Aby warping y or bucklingof the shell, the heads, orthe trunnions as a result of operation or temperature conditions.

In another prior mill, one of the trunnion bearings is eliminated andthe shell is provided near itsinlet end withv a slide ring mounted on slide shoes,` the ringand shoes being enclosed within a casing- This construction is less expensive than the mill provided with the two trunnion bearings, but is objectionable by reason of the necessity of providing three casings, one for the inlet scoop, one for the slide ring'and shoes, and one for the master gear and driving pinion. In a furtherdevelopment of themill of the second type, the

slidering with its shoes is placed centrally of the drum so Vas to bear substantially the entire load.

This permits replacement of the trunnionbearing construction; is reduced, but again, the millin-` cludes thefthree 'casings above mentioned.

The present 'invention is directed ,tothe 'provi'-A sion'of a mill or similarapparatus including. a

generally cylindrical shellmounted for. rotation on its longitudinal axis .which is ,Y superior to the prior constructions described in that it -is lower in'cost and simplerinerection, andthose partswhich require attention and lubrication 'are more readily accessible., Atithe same-time, diculties arising from misalignment of the parts because' of warping or bucklingare largely eliminated.

In the new apparatus .in the forni, for example, of a ball mill, the shellhasanrinlet atone'end,

whichY may be provided=withean inlet scoop of Vusual construction, hasan outlet at the other end, and rhas aguidebearng at one end to prevent themill from tilting. Betweenits ends, the

`mllis encircled by-a ringwhich is secured to the shelllandihas -a peripheryformed with adjacentcircumferential sections, rone of which has, a

smooth' surface .and another Ot-Which is formedv as a gear. The shell is rotated by meansof a pinion meshing with the teeth of the gear section and it isL supported .for rotation on supporting means engagingthefsrnoothsection.. With the.

driving andlvsupportin'gmeans placed close togetheratlthe middle of the shell, these parts can 'all be enclosed .within a single casing. Prefer ably, the ring encircling the shelljis formed with ay pairjof gearsectionsuvwhich mayj have teeth corresponding., respectively, to the two .halves Y of a herringbone gear. are employed, theshaft carries two pinions and is supported in a bearing lying between the pin-A When two. gear sections Fig. 1 is a view 'in' sideelevation, with parts shown in section ontheline l-I of Fig. 2, of one form of apparatus constructed'in accordance with the invention;

Fig. 2 is a'sectlonal view of the apparatus shownin Fig. y1 on the line -2-.2l of Fig. 3;

Fig; 3 is another sectional view on the line 3-,3`

of'Fig.2; and. 1

i Figs. Y4 and 5 areifragmentary elevational views'.

A the invention,

I'I on a standard I8. This bearing, which is only,

for the purpose of preventing the mill from tilting about the main support, carries little or no load and can, therefore, beof very `small size.

If preferred, a trunnion bearing maybe provided between the scoop and the mill body, in which event, the shaft I6 andits bearing I 1 may be eliminated. The scoop dips-into a bodyhof' 'material I9 contained within a pit 20 and is enclosed within a casing 2I provided with appropriate means for sealing the "shafti andthe koutside ofv inlet-f3; The end rsection I2 is vprovided with a tubular outletA l'22 fwhch extendsfintothe sta-v tionary discharge casing 23;VI The shell, the scoop, and the other features Yabove described 'are of conventional construction. l

Encircling the shell substantially. Amidway between its endsis a ring. 24'which`isrprovided with anwinwardly extending-web 125wl'1ich'may be bolted .tobrackets26'welded or otherwise secured tothe outer. surface of shell I0.- The .member 24 has a smooth peripheral` section21 lying between adjacent peripheral sections-128, both of whichare surface of shaft 31.

formedwith'gearteeth, and, 'inthe construction shown, the outer diameter ofthe -smooth section islessthan that of they gear sections. It" will Abe understoodhowever, that the smooth section may beof=the same outer'diameter as the gearsec'- tionsior of `greater diameter, as desired. Extendinginwardradiallyalong each edge of ring 24 isa vflange 28 and the-ring `isreinforced bywebs 30 extending from ,the inner-surface of eachflange andthe under surface ofthe periphery of the ring to web'25.

The smooth section 21 ofring 24may serve as` a tire running on vsupporting rollers or as a slide ring sliding on shoes. The latter constructionis illustrated and the smooth section runs on slide shoes 3| supported on standards'32' on a vfoundation v33. Preferably each vshoe, is" mounted Afor universal movementand, 'forthispurpose it is provided on its'under surface with Va ball shaped insert 34 resting in a cup 35 on the, top of the. standard 32. 1

Theshell is rotated by means of a pairofpin-fV ions 36'mounted on a shaft'31. In theconstruction shown inV Fig. 1. the.gearsections28 have.

teeth similar, respectively, to those of thehalves of a herringbone. gear and, theipinionst` have teeth of approoriateshapeto mesh. withthegear sections. Shaft 31 is mounted in a bearing. 38 between the pinions and the, bearing preferred for the purpose is one which is selfi'aligning in theplane of tooth pressure. Shaft 31,. is connected at one end through a fiexible'coupling 39' toa shaft 40jrunnin'g iny a bearing4 I on the foundations-'42 and connected through'a flange coupling 43 tothe shaft 'o1'l theA driving motorY 44'. 'I'he weight of half the coupling 39lattached vto oneend of shaft-"Slitendsito' causetheeshaft to tilt in its bearing 38 and thistendency may be overcome tby applying :a-f-counterweight to: the other end of the shaft or subjectingv it'tosprin'g pressure: 'Phe-flatter,Y construction lis illustrated and it includes a bearing 45 in which the free end of the shaft runs and which is pressed downwardly by a spring 46. The pressure of the spring is adjustable by a screw 41 mounted in the wall of casing 4S surrounding the end of the shaft and the spring serves to equalize the load on opposite ends of the shaft.

The ring 24, with its smooth and gear sections, the. driving pinions 36, and theslide shoes 3l and their supports are all enclosed within a casing de which encircles the shell. This casing prevents access of dust to the Dinions, gear sections,

and slide shoes and is provided with sealing means, such as. feit rings 50 bearing on flanges 2S1on.ringf24`,'and sealing ring 50a bearing on the As ring 24 serves as part of both the driving and supporting means, a single casing is suicient to enclose these two means. The casing rests on the foundation 33 and may be made of a number of parts bolted together, as indicated in"Fi`g. 2, so that by removal of one ci' more parts of the casing; access may be readily had tothe-pinions,v bearing 38; andthe slide shoes 3I. K

In' the constructionshown in Figs. l1 to I3, the ring 24 is preferably made in one piece so that it completely encircles the shell andfmay be secured thereto by bolts. Howeventhe ring may bemade in sections, each of which'is' preferably a single section, although each section maybe madef of two or more pieces bolted -orA otherwise secured together.'v

In the mill shown in Fig. l, rthe yweight of the shell'and its contents is borne substantially entirely by the shoes 3| sliding on the smoothsection 21 ofring 24'. If-this sectionv is of'less outer diameter than the gear sections 28 on either side thereof, additional space is provided'opposite the smooth section for the bearing 38- of shaft'r 31 carrying the driving `pinions 3G. The'bearing 38 is' self-aligning as described and; as a resultzhe same tooth pressure isobtainedy on each pinion.

In the construction shown'in 4, 'the shell 5I is provided as before with an inlet at one end receiving material from a scoop, and an outlet to the other; .The shell isV encircled by a Vring 52 having a smooth 'centralsection'53'and' gear sec'- tions 54V on either side thereof; The .gear sections' illustrated have teeth of the spur type and these teeth mesh with similar teethA on pinions 551on a shaft 55 supported in a bearing 5T between the. pinions and mounted on a block 58. Shaft 56 isv also mounted in another bearing 59 and is connected through a coupling 60 tothe shaft of a motor 6I.,v The shell 5Il maybe supported for rotation on rollers or onslide shoes actingy on thesmooth section 53 of ring 52 and .it is-rotated by pinions 55 meshing. with gear sections-54i The supporting means .fortheshelL thering 52,.'and the pinions 55 and associated parts are enclosed within a singlecasing E2 lsupported on the foundation 63. In the constructionl shown in Figui, the bearing 51 is not self-aligning, ,but a bearing similar to bearing. 38 of Fig. 1 may be employed with this construction, provided shaft 56 sfdivided into two sections vsimilar to shafts 31 and. illV and coupled by va flexible coupling,` the: fre end section beingsuitably balanced.

In someY instances, it maybe desirabletoi pro videonly: a vsingle master gear for: rotating the shell .and such Aa Vconstructionisiillustrated.; in

Eig.' 5; In that construction,v the. Miencr-i cling. sheli .65. hasf. 'a smooth section A66 @and fa single gear sectionzGT. Apinioni: ona shaft? 69 mounted in bearings 10 Y'and 'Il l,engages gear. 61` and the smooth section 66`serves as theslide ring forfslide shoes 12; yThe ymember 64, thefslide shoes, pinion, and shaft bearing 10. areall mounted within a single casing 13 `which prevents dust fromreaching these parts. Y

In the new mill, the provision 'of a single member, such as ring 2li which includes both a smooth section servingas a slidering' or a tire, and one or two gear sections, simplifies the construction and reduces the cost. This ring, together with the supporting means and driving pinions,-can

be enclosed within a single casing through whichV access may be had to the supporting 'and driving means for lubrication and other care.y The construction described is simpler in erection-and requires simpler foundations than prior,r similar mills and by bringing all vthe Jelements of the driving and supporting means into vone integral unit, misalignment resulting from warping or buckling of the shell, the heads, and other parts caused by operating or temperature conditions or by'uneven settlement of foundations is largely eliminated. l

1. Apparatus of the type described, which comprises a generally cylindrical shell, a member encircling and secured to the shell and having adjacent peripheral sections, one having a' smooth surface and another formed as agear, a foundation, supporting means on the foundation engaging said smooth section to support the shell for rotation, a shaft, a pinion on the shaft meshing with the gear section to rotate the shell, and a casing on the foundation encircling the shell and enclosing the member, supporting means, and pinion, the shaft extending through the wall of the casing.

2. Apparatus of the type described, which'comprises a generally cylindrical shell, a member encircling and secured to the shell and having adjacent peripheral sections, oneY Vhaving a smooth surface and another formed as a gear, a foundation, slide shoes mounted on the foundation and engaging said smooth section to support the shell for rotation, a shaft, a pinion on the shaft meshing with the gear section to rotate the shell, and a casing on the foundation encircling the shell and enclosing the member, shoes, and pinion, the shaft extending through the wall of the casing. Y

3. Apparatus of the type described, which comprises a generally cylindrical shell, a member encircling and'secured to the shell and having adjacent peripheral sections, one having a smooth surface and another formed as a gear, the outer diameter of the smooth section beingless than that of the gear section, a foundation, supporting means on the foundation engaging said smooth section to support the shell for rotation, a shaft, a pinion on the shaft meshing with the gear section to rotate the shell, and a casing on the foundation encircling the shell and enclosing the member, supporting means, and pinion, the shaft extending through Vthe wall vof the casing.

4. Apparatus of the type described, which cornprises a generally cylindrical shell, ka member encircling and secured to the shell and having adjacent peripheral sections, one having a smooth surface and another formed as a gear, the outer diameter of the smooth section being less than that of the gear section, a foundation, slide shoes mounted on the foundation and engaging said smooth section to support the shell for rotation,

Y the casing'.

a shaftga pinion on the shaft meshing .with the gear section to rotate the shell, and a casing on the foundationencircling 'the'shell and enclosing the member, shoes, and pinion, the'shaft extending through the wall of the casing.

5. Apparatus of the-type described which comprises a generally vcylindrical shell, a member encircling and secured tothe shell. andhaving a pair of peripheral gear sections anda smooth surfaced peripheral section between the gear sec-r tions, a foundation, 'supporting means onvthe foundation engaging the smooth section and supporting the shell for rotation,l a shaft, a pair of pinions on the shaft meshing with' yrespective gear sections torrotate the shell,and a casing von the foundation encircling theshell and enclosing the member, supporting means, and pinions, the shaft extending through the wall of 6. Apparatusof the type described which comprises a generally cylindrical shell, a member encircling and secured tothe shell and having a ,pair of peripheral gear sections and a smooth surfaced peripheral section between the gear sections, the outer diameter of the smooth section being less than that of the'gear sections, a foundation, supporting means on the foundation engaging the smooth section and supporting the shell for rotation, a shaft, a pair of pinions on the shaft meshing with respective gear sections to rotate the shell, and a casing on the foundation encircling the shell and enclosing the member, supportingmeans, and pinions, the shaft extending through the wall of the casing.

7. Apparatus of the type described which comprises a generally cylindrical shell, a member encircling and secured to the shell and having a pair of peripheral gear sections and a smooth Y surfaced peripheral section between them, the

gear sections having teeth of the shape of those of respective halves of a herringbone gear, a

' foundation, supporting means on the foundation engaging the smooth section and supporting the shell for'rotation, a shaft, a pair of pinions on f the shaft meshing with respective gear sections to rotate the shell, and a casing on the foundation encircling the shell and enclosing the member, supporting means, and pinions, the shaft Y extending through the wall of the casing.

8. Apparatus of the type described which cornf prises a generally cylindrical shell, a member encircling and secured 'to the shell and having a pair of peripheral gear sections and a smooth surfaced peripheral section between then-na foundation, supporting means on the foundation engaging the smooth section and supporting the shell for rotation, a shaft, a bearing for the shaft lying in alignment with the smooth section, pin- Aions on the shaft meshing Vwith the gear sections,` and a casing on the foundation encircling the shell and enclosing the member, supporting means, bearing, and pinions, the shaft extendf ing through the wall of the casing.

9, Apparatus of the type described which comprises a generally cylindrical shell, a member encircling and'secured to the shell and having a pair of peripheral gear sections and a smooth surfaced peripheral'section between them, a foundation, supporting means on the foundation engaging the smooth section and supporting the shell for rotation, a shaft, pinions on the shaft meshing with the gear sections to rotate the shell, a single bearing for the shaft, the bearing lying between the pinions, anda support on the foundation on which thebearing is mounted for sell'- alignin'gmovementl ini a .plane 1 generally parallel* tothefplaneLof-pinin tooth pressure. f v

10:. Apparatus 'ofthe typedescribedwhich'eom prisesra generally' cylindriealfshellg-a member: en:- circling and secured tof-the ish'ellvand'v having-aa pair sof peripherals gearf sectiens and a -sxnoo'th surfaced peripheral'seetioxifbetwen them,=a foundation, supporting means 'onftheffoundation 'en gag-ing i they smooth'- sectioxr and supporting ethe shell for rotatienf a shaft; pinionsf on the shaft meshing with thegearsections to rotate the shell,-v a single-bearing-x for. the shaft; the bearing llying between v.the Apinions and I'mounted vfonthe` foundationfor self-'aligning-movement in a planegen-4 era'lly- Aparallel tot-he planey of y pinionl toothl pressure, fa second-shaft valigned withl the pinionshaft, connected coupling-members on the adjacentl ends of the'shaftsfandvmeansengaging the other end of the pinion shaft to balance the Weightnt` the couplingmember carried thereby.;A

1 l. f Apparatus -of the typefdeseribed f which conn prises -a generally cylinelrieahshell,` a `member encircling theshelland havingva-adjacent peripheralsections,Y onehaving-la smooth surface and another formed as'ia gearpthelmember having a Web-extending inwardly and securedto the shell, a founclation-,v 4 supportingV means on `the foundaing thei'shellfforrotation;'a shaft; 4a IJinionf:on'l

the'shaft meshing=withl the gear-sec-tion-to rotate the shell? fa bearingffor-the shaft in.v alignment with the smooth:section, -and v-a -casingf' on ythe foundation enclosing the member, V`pinions, bearing, a and 'supporting means, lthe shaft extending through the -Wall ofthe casing.

12. Apparatus-0f the Atype described, which comprises a generallyfcylindrical shell, a member encircling Iand secured to the shell and having adjacent peripheral' portions, one having a Smooth surfacev andanotherformed asfa gear, a foundau f pinion, the lpinion shaft extending through one wall of the casing. y

' LOUIS S. PETERSEN. 

